Smithsonian - National Museum of American History, Behring Center

 
Physical Sciences Collection - Surveying and Geodesy

Browse Makers | Browse Instruments | Index
 

Browse by Instrument
 

Alidade
Altitude and Azimuth Instrument
Chain, Tape and Base Bar
Compass, Pocket
Compass, Railroad
Compass, Solar
Compass, Surveyor's
Cross, Surveyor's
Electromagnetic Distance Measurement (EDM)
Gradienter
Graphometer
Heliotrope
Holland Circle
Level
Range Finder
Repeating Circle
Theodolite
Transit
Transit and Equal Altitude
Transit, Geodetic
Universal Instrument
Vertical Circle
Waywiser
Zenith Telescope
Miscellaneous

 

Graphometer

A graphometer consists of a graduated semicircle with a pair of sight vanes at either end, and a movable alidade with another pair of sights at either end. The form was introduced in Philippe Danfrie, Déclaration de l’usage du graphomètre (Paris, 1597), and was always popular in France. Many graphometers have an inset magnetic compass. Most graphometers are made of brass, but some American ones are made of wood. Some 19th-century graphometers had telescopes rather than open sights. Graphometers were also known as semi circles or semicircumferentors.

Ref: J. A. Bennett, The Divided Circle (Oxford, 1987), pp. 49–50.

Collection:

Bosworth (1823)
Bosworth (1824)
Delure
Lerebours
Lilley’s patent
Lutz
Meurand
Pike Jr.
Secretan
unmarked (Engineering Societies’ Library)
unmarked (Fordham University)
unmarked (St. Mary’s College)